Joint for chair-seat sections or similar purposes.



No. 754,067. PATENTED MAR, 8,1904.

J. B. HOUGH. JOINT FOR CHAIR SEAT SECTIONS 0R SIMILAR PURPOSES.

APPLICATION FILED MAY 1, 1903.

N0 MODEL.

Patented March 8, 1904. M

PATENT OFFICE.

JOHN BRUCE HOUGH, OF ERVING, MASSACHUSETTS.

JOINT FOR CHA lR-SEAT SECTIONS OR SIMILAR PURPOSES.

SPECIFICATION formingpart of Letters Patent No. 754,067, dated March 8,1904.

Application filed May 1, 1903. Serial No, 155,135. (No model.)

To aZZ whom it may concern:

Be it known that 1, JOHN BRUCE HOUGH, a citizen of the United States,residing at Erving, in the county of Franklin and State ofMassachusetts, have invented a new and useful Joint for Chair-SeatSections or Similar Purposes, of which the following is a specification.

This invention relates to an improved joint especially designed foruniting the pieces which are glued together in manufacturing chair-seatsand which can also be employed for other purposes.

The especial object of this invention is to provide a strong, simple,and efiicient form of tongue-and-groove joint which may be used to makestronger and more efiicient connection between wooden sections withoutmaterially increasing the expense of making the same.

To these ends this invention consists of an improved joint of achair-seat as an article of manufacture having its parts connected bysuch joints and of the combinations of parts therein, as hereinafterdescribed, and more particularly pointed out in the claims at the end ofthis specification.

In the accompanying drawings, Figure 1 is a perspective view of theparts which may be employed in making up a chair-seat according to thisinvention. Fig. 2 is a transverse sectional view illustrating thebreaking leverage of an ordinary tongue-and-groove joint. Fig. 3 is atransverse sectional view of a joint constructed according to thisinvention, and Fig.

4: is a side View of one of the chair-seat pieces.

In manufacturing wooden chair-seats of that class to which thisinvention relates wooden strips or pieces are first glued together toform a chair-seat blank. This blank is afterward rounded to properoutline and is molded or concaved and bored to receive the chair-legs orother fixtures which support the same.

One objection to a glued-up chair-seat arises from the difliculty ofsecuring sufiiciently strong joints to unite the pieces or strips whichmake up such a chair-seat.

In practice chair-seat pieces have sometimes been matched together withordinary tongueand-groove joints. Usually, however, plain 5 O gluedjoints are relied upon to fasten the chairseat pieces together. This inpractice has.

been found to be objectionable, as the glued joints are liable to giveway, so that the chairseat pieces may break by permitting the chair tocome to pieces.

In practicing this invention it has been found that by uniting pieces ofa chair seat by tongue-and-groove joints which extend diagonally acrossthe contact-faces of such pieces the strength of the chair-seats of theclass referred to may be materially increased without greatlyincreasingthe cost of manufacturing the same.

The strength of a joint constructed according to this invention maybeattributed to the fact that the diagonal location of the tongue andgroove increases the breaking leverage of the joint and also to the factthat the tongue, which is preferably integral with one of the pieces,has its grain running across the same at an angle.

The accompanying drawings illustrate the application of jointsconstructed according to this invention in the manufacture of athreepiece chair-seat. It is to be understood, however, that thisinvention is also applicable to other constructions besides that of achairseat, as such joints may be used with advantage in tight'cooperage,barrel-heads, tabletops, box-boards, and, in fact, in nearly allstructures where wooden pieces are joined together and require towithstand any considerable degree of breaking strains.

Referring to-the drawings and in detail, the chair-seat thereinillustrated comprises the sections A, B, and C. Extending from the facesof the sectionsB andCare integral diagonallyarranged tongues 10,whichfit into corresponding diagonally-arranged grooves 11. The increasedstrength secured by this form of joint can be understood from aconsideration of the sectional view, Figs. 2 and 3.

In Fig. 2 twowooden pieces are illustrated as connected by an ordinarytongue andgroove joint located near the bottom, as is sometimes thepractice in making chair-seats. In an ordinary joint of this kind thegreatest leverage that the tongue and groove have in resisting thebreaking or bending of the parts to the position illustrated by dottedlines is the distance a b, whereas in a joint constructed according tothis invention, as illustrated in Fig. 3, at some point along the jointthe tongue and groove have a breaking leverage equal to the length abthat is to say, at some point along the length of a joint constructedaccording to this invention, no matter from which side the strain isapplied, the tongue and groove will have a breaking leverage ofsubstantially the entire width of the meeting faces. In addition to thisthe breaking strength of the integral tongue or projection 10 isconsiderably more than in ordinary joints in which the tongue isparallel with the grain of the wood. This is best illustrated in Fig. 4,from which it will be seen that the grain of the wood crosses the tongueat an angle, so that before the tongue can be broken or sheared off agreater number of wood fibers will have to be pulled apart than would betorn apart in shearing ofl an ordinary tongue.

I am aware that joints constructed according to-my invention maybeapplied and used to advantage in many other constructions besides thatof the chair-seat which I have herein shown and described and thatnumerous changes may be made by skilled mechanics, according to thespecial use which is desired to be made of the joints. For example,while I have illustrated a single diagonally-arranged tongue-and-grooveconnection between each of the adjacent pieces, for some purposes it maybe desirable to use two or more diagonal tongues, and the pitch orrelative inclination of the tongues may be changed according to thespecial location to which the joints are to be applied. I do not wish,therefore, to be limited to the construction I have herein shown anddescribed; but

What I do claim, and desire to secure by Letters Patent of the UnitedStates, is

1. As an article of manufacture,'a Wooden structure comprising aplurality of separate pieces or strips connected together by tongues,each of which extends diagonally across the engaging face of a section,and which projects a uniform distance from the surface thereof, andwhich is seated in a groove of uniform depth extending diagonally acrossthe meeting face of an adjacent section.

2. As an article of manufacture, a wooden chair-seat comprising aplurality of separate pieces, the joint between adjacent piecescomprising an integral tongue projecting a uniform distance at allpoints in its length from a meeting face of one of said pieces, andextending obliquely acrosssaid meeting face, and fitting into a grooveof uniform depth which extends obliquely across the meeting face of anadjacent piece.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

JOHN BRUCE I-IOUGH.

Witnesses:

HARRY N. BLACKMER, ELBERT J. HOLLAND.

